Mail assorting device



Oct 18, 1966 M. G. BARNARD ET 3,279,598

MAIL ASSORTING DEVICE Original Filed Dec. 21, 1961 4 Sheets-Sheet l I ENTORS "\onlRDE a. mzumw wmxee 5. Hanson BY Lmaemce M. Vfiw -AK 1956 M. G. BARNARD ETAL 3,279,598

MAIL ASSORTING DEVICE 4 Sheets-Sheet 2 Original Filed Dec. 21. 1961 III/? Oct. 18, 1966 M. G. BARNARD T AL 3,279,598

MAIL ASSORTING DEVICE Original Filed Dec. 21, 1961 4 Sheets-Sheet 4 INVENTORS memos 61. Bamako w HLT R 3. Hanson Y uwgencc .N- (M HOLAK United States Patent 3,279,598 MAIL ASSORTING DEVICE Monroe G. Barnard, Westport,.Walter J. Hanson, Old Greenwich, and Lawrence N. Varholak, Fairfield, Conn., assignors to Pitney-Bowes, Inc., Stamford, Conn., a corporation of Delaware Original application Dec. 21, 1961, Ser. No. 161,117, now Patent No. 3,236,355, dated Feb. 22, 1966. Divided and this application May 17, 1965, Ser. No. 470,283

4 Claims. (Cl. 209-72) This is a division of application Ser. No. 161,117, filed Dec. 21, 1961, now Patent No. 3,236,355 for an apparatus for handling pieces of letter mail to orient the latter preparatory to performing operations thereon such as any one or more of facing, stamp cancelling and sorting.

Mail, when picked up and delivered to a post oflice for transmittal is, in large part, non-oriented and includes packages, newspapers and other articles along with letter mail. After culling out all but the letter mail, the latter (which includes post cards as well as filled envelopes) is ordinarily faced (arranged in groups with all of the stamps facing in one direction and located at one corner), cancelled (by overprinting the stamps with a cancellation .mark) and sorted (according to class and destination).

With the apparatus of the present invention, the nonoriented pieces of letter mail are oriented by causing them to flow in a roughly regulated stream, then de-clumping the letter mail pieces of this stream, then causing the letter mail pieces to be edged and further streamed by acting upon them to bring one of their longer edges against guide means and accelerating their rate of flow, and then delivering the pieces of letter mail in the proper attitude for stacking or farther processing; all this being preparatory to said facing, cancelling and sorting operations.

Accordingly, an object of this invention is to provide a new and improved apparatus useful in handling pieces of letter mail for orienting the same.

Further objects of the invention include providing such as apparatus which incorporates means for causing pieces of batch mail which have been de-clumped and streamed the de-clumped pieces of the stream to be edged and further streamed.

Another object is to provide an improved apparatus for edging and streaming pieces of letter mail. Further objects are to provide such an apparatus which is effective to turn letter mail pieces from edged condition at one of their respective shorter edges to edged condition at one of their longer edges, which is effective to withdraw so-called fiats from the stream, and which is effective to deliver a stream of edged pieces of letter mail in the proper attitude for stacking or further processing.

Further objects and advantages will become apparent as the description proceeds.

An embodiment of the invention is shown in the accompanying drawing wherein:

FIG. 1 is a perspective view of a letter handling apparatus according to the invention, this-view including an inclined conveyor unit, a chute, a rotary edging and streaming unit, a letter turning unit and a tandem facercanceller unit;

FIG. 2 is atop plan view of a portion of the inclined conveyor unit, the chute, the rotary edging and streaming unit and the letter turning unit;

FIGS. 3 and 4 are fragmentary sectional views taken along the lines 33 and 44, respectively, in FIG. 2;

FIG. 5 is a fragmentary elevational view of a presser member;

FIG. 6 is a fragmentary top plan view of a portion of the rotary edging and streaming unit which includes a flat-snatcher;

FIG. 7 is a fragmentary elevational view of the struc- 'ture shown in FIG. 6; and

FIG. 8 is a schematic wiring diagram for the mail handling apparatus.

Referring to FIG. 1, an apparatus embodying the pres ent invention is shown as including an inclined conveyor unit, a chute, a rotary edging and streaming unit, a letter turning unit and a tandem facer-canceller unit generally designated at 20,. 22, 24, 26 and 28, respectively. These respective units will be described in the order in which they operate upon the pieces of letter mail to orient the same.

With reference to FIG. 1, the inclined conveyor unit 20 represents an improvement over the feeding unit disclosed in copending US. patent application Ser. No. 15,- 336, filed on Mar. 16, 1960 by F. J. Liberty et al., now US. Patent No. 3,061,067, dated Oct. 30, 1962. The unit 20 includes a frame 30 which supports a guideway having upstanding sides 32, 34 and a flat bottom 36. The lower end of the guideway takes the form of a hopper 38 for receiving batches of non-oriented pieces of letter mail of mixed widths, lengths and thicknesses.

Endless belt 50 passes around rollers 44 and 48 and is driven through a conventional speed reduction unit 66 connected by belt to pulley 72 on roller 48.

Pieces of letter mail are carried up and driven off the upper end of the inclined endless belt 50 under rollers 94, in a regulated stream by the inclined conveyor unit 20. The successive pieces drop into a chute 22 from the inclined conveyor unit 20. As shown in FIGS. 1 and 2, the upstanding sides 32, 34 of the guideway of the unit 20 are forwardly extended to form respective portions of the chute 22. The extension of the guideway side 32 stands substantially vertically, the extension 172 of the guideway 34 is integral with a downwardly and inwardly inclined section 174 which joins, as does the vertical extension 170, one side of a downwardly and forwardly inclined bottom chute section 176. As can be seen in FIG. 2, a forwardly and downwardly inclined section 178 extends between the extensions 170 and 172, and connects with a forwardly and more steeply downwardly inclined section 180. The section 180 extends between the section 174 and the extension 170, and also joins with the bottom chute section 176. The successive pieces of letter mail, after they fall into and slide along the chute 22, tend to arrive at the discharge end of this chute with one'of their shorter edges foremost; this being due, in part, to the transverse dimension of the bottom chute section 176 which is greater than the width but smaller than the length of most pieces of letter snail.

Under'the impetus of sliding down the chute 22, the successive pieces of letter mail move onto the upper surface of an annular disc 182 of the rotary edging and streaming unit 24. This unit 24 represents an improvement over the rotary edging and streaming unit disclosed in the above-cited US. patent application Ser. No. 15,336, now US. Patent No. 3,061,067, dated Oct. 30, 1962. The annular disc 182 is supported for rotation about a vertical axis and in the clockwise direction as viewed 'in FIG. 2 by three substantially equally spaced rollers 184. Each of the rollers, as shown in FIG. 4, is supported for free rotation about a horizontal axis by a yoke bracket 186 fixed to the upper surface of a circular supporting table 188. The table 188 is supported, in turn, by a plurality of legs, not shown.

Stability of the annular disc 182 against horizontal shiftingis elfected by three rollers 192, 194 and 196 (FIG. 2). The annular disc 182 is fixed to or integral with a pair of downwardly extending rigidifying flanges 198 and 200, respectively, and each of the rollers 192, 194 and 196 bears against the radially inner surface of the flange 200 to provide this horizontal stability. The annular disc 182 is rotatably driven by the roller 192. As shown in FIG. 4, the roller 192 is fixed to a shaft 202 supported for rotation by a bearing bracket 204. The bearing the sprocket wheel 208 and with another sprocket wheel 212 fixedly carn'ed by the shaft of a motor 214 (FIG. 2).

The motor 214 is supported by the table 188 and, when energized, rotatably drives the annular .disc 182 through the sprocket chain 210. and roller 102 The rollers 194 and 196 are supported in a manner similar to that of the driving roller 192 except that each of the rollers 194 and 196 is a freely rotatable idler roller rather than being a 7 driving roller.

The upper surface of the annular disc 182 is formed by an annular strip 216 of friction material such as rub- :ber whereby the coefficient of friction between the upper surface of the annular disc and a piece of letter mail is greater than that between two pieces of letter mail.

Disposed about a substantial portion of the periphery of i the annular disc 182 is an upstanding arcuate guide 218.

The arcuate guide 218 is formed of a plurality of tandem sections and is secured along its length to the outer periphery of the table 188. As pieces of letter mail move onto the upper surface of the annular disc 182 from the chute 22, these pieces are moved .by the disc 182 in the direction of rotation thereof and are urged by centrifugal force against the arcuate guide 218.. Being so urged, against the guide 218, these letter mail pieces are edged, that is, one of the respective edges of each of the pieces moves into engaging registration with the arcuateguide. The speed of rotation of the annular disc 182 is sufficient that the letter mail pieces .slip or lag relative to the disc throughout all or at least a substantial portion of the arcuate path followed by these pieces. Since the meth- .cient of friction between two pieces of letter mail is less the table 188 directly over an than that between the friction surface of the annular 'disc .182 and a piece of letter mail, the tendency is for 'the lowermost one of two or more overlapping pieces to be driven out from under and forwardly of the remaining piece or pieces. In this manner, not only is additional edging of the letter mail pieces accomplished but so also is additional streaming effected. It will be understood by those skilled in the art that the term streaming refers to separating, in the direction from lead edge to lead edge, articles being fed along a feedpath.

As previously noted, most of the letter mail pieces leave the chute 22 with one of their respective shorter edges foremost due, in part, to thebottom chute section 176 being of a width greater than the width of mostpieces of letter mail but smallerthan the length of these pieces. Another feature that aids in effecting this result lies in thereof to ride against the chute section 174 in elevated location relative to the other shorter edge of that piece; this other shorter edge ordinarily riding at or close to the junction of the sidewall 170 and the bottom chute section 176. As a consequence this latter shorter edge rides onto the upper surface of the annular disc 182 at the location below the cut-out 219 while the elevated shorter edge thereof is in engagement with the chute section 174. The

tendency is for the shorter edge engaging the upper surface of the annular disc to be driven forwardly of the elevated shorter edge whereby the piece of letter mail is turned to bring the driven shorter edge foremost. Occasionally, however, one of the letter mail pieces will have one of its shorter edges register with the guide 218 as shown, for example at L' in FIG. 2.. The manner in which this condition is accommodated by the unit 24 will now be described.

A presser. member 220 isprovided which includes a hub 222 supporting a circular brush 224formed of flexible bristles which extend radially outward from the hub 222 (see FIGS. 2 and 5). The hub 222 along with the brush 224 is rotatable freely about one end of a crank mm 226. The opposite end of the crank arm 226 is retained for free rotation by a bearing block 228. mounted on a circular cover plate 230 later to be described in detail. As shown in FIG. 5, the presser member 220 can be set in adjusted position transversely of the upper surface of the annular disc 182 .by loosely inserting the endof a set: screw 232 in a selected one of a pluralitypf grooves 234 in the crank arm 226. By setting the presser member 220 in a transverse position such that it lies a distance from the guide 218 slightly greater than the maximum width of the letter mail pieces to be handled (this will be less than the length of the shortest pieces to be handled), a letter-mail piece in the attitude of the letter L in FIG. 2 will be swung or turned in a horizontal plane to bring its leading longer "edge into edged condition against the guide 218. In this regard, the presser member 220 acts in the same manner as its counterpart in said copending US. patent application Ser. No. 15,336, now US. Patent No. 3,061,067, dated Oct. 30, 1962, in the respect that under the weight of its parts, the presser member urges each piece of letter mail passing thereunder into firmer driven engagement with the annular disc. Since each piece of letter mail slips or lags behind the annular disc, the effect of the downward urging of the presser. member is to cause the annular disc to drive the portionof the. letter mail piece pressed thereagainst, ahead and about the leading corner of that piece at the guide 218. The resulting counterclockwise turning (as viewed inFIG. 2) of the letter mail piece brings the leading longer edge" of the piece. into edged condition against the guide 218; all this as the piece continues to move along the arcuate path defined ,by the guide 218.

The previously mentioned cover plate 230 extends along a substantial portion of the length of the arcuate path followed by' the pieces of letter mail as they move into edged condition against the arcuate guide218u The cover plate 230 provides a cut-out portion 235 to accommodate radial adjustment of the presser member 220. t The cover plate 230 is preferably formed in separately connected sections and is preceded by acover plate 236 attached vto the arcuate guide 218 in the same manner as the. cover plate 230. The lead-in end of the cover plate 236 is formed with an inclined portion 238 which acts to de-. 'flect pieces of letter mail-toward the annular disc 182' from the chute 22.1

When the annular disc 182 rotates, the air directly therevabove tends to be urged radially outwardly by centrifugal force just as are'the pieces of lettermail. Since the cover plates 230, 236 extend radially inwardly from the guide stantially confined for movement in the direction of move-1 ment of the annular disc. This acts to decrease the planing effect of letter mail pieces. In this regard, the pieces of letter, maiL particularIy those with an upwardly bent leading end, tend to liftoff the friction surface of the annular disc as they move past the air thereabove. With this air moving in the same direction as theletter mail 'pieces, h'owever, this tendency is decreased.

Another presser member 240 is provided as shown in FIGS. 2 and 3. The presser member 240 takes the form of a flap formed of a flexible material such as rubber. The flap 240 is supported by a bracket 242 secured to the cover 'plate 230. The flap 240 extends from the bracket 242 through aspace, between the cover plates 230, 236 into converging relation with the upper surface of the annular disc 182 in the direction of movement of the latter.. The presser member 240 acts, as do its counterpart presser members in the above-cited US. patent applicationSer.

No. 15,336, now US. Patent No. 3,061,067, dated Oct.

30, 1962, to urge the successive pieces of letter mail into firmer driven engagement with the disc 182 thereby to increase the edging and streaming efliciency of the unit 24.

It sometimes occurs that so-called flats or oversize pieces of letter mail such as that shown at L in FIG. 2 are delivered by the unit 20 and chute 22 to the unit 24. Such pieces are greater in width than the maximum to be handled, and a flat-snatcher generally designated at 244 in FIGS. 2, 6 and 7 is provided to discharge such pieces from the system automatically. The flat-snatcher 244 includes a series of three driven rollers 246, 248 and 250, each of which is similarly fixed on a respective shaft 252 rotatably mounted in a respective bearing block 254 secured to the table 188. An enlarged diameter portion of the shaft 252 on which the roller 246 is fixed, is driven through a universal joint 256, a drive shaft 258, a universal joint 260, a shaft 262, and a pair of pulley wheels 266, 268 about which an endless belt 270 is entrained; the pulley wheel 268 being driven by an electric motor 272. The shaft 262 is rotatably supported by a bearing block 274. The bearing block 274 and the motor 272 are supported by respective brackets (not shown) which 'are carried by the table 188.

As best shown in FIGS. 6 and 7, a pulley wheel 276 is fixed on the shaft 252 mounting the roller 246, a pair of pulley wheels 278 and 280 is fixed on the shaft 252 mounting the roller 248, and a pulley wheel 282 is fixed on the shaft 252 mounting the roller 250. An endless belt 284 drives the pulley wheel 278 from the pulley wheel 280 and an endless belt 286 drives the pulley wheel 282 from the pulley Wheel 280. Each one of three idler rollers 288, 290 and 292 opposes and is resiliently biased toward a respective one of the three driven rollers 246, 248 and 250. In this regard, each one of the idler rollers 288, 290 and 292 is rotatably supported by a yoke member 294 which is resiliently biased downwardly by a torsion spring 296 in conventional fashion about a pivot pin 298 secured to a contoured plate 300. The plate 300 is carried by a bracket 301 mounted on the table 188.

Each pair of rollers 246 and 288, 248 and 290, and 250 and 292, diverges, as best shown inFIGS 2 and 6, at an angle from the feed path of pieces of letter mail on the annular disc greater than that at which the respectively preceding one of these pairs of rollers diverges. Also, the bite between the pair of rollers 246, 288 is disposed radially inwardly of the annular disc 182. This roller bite will be located at a distance from the arcuate guide 218 slightly greater than the maximum Width of letter mail pieces to be handled. As a consequence, a so-called flat which is being impositively driven by the annular disc 182 will enter the bite between the rollers 246, 288 and will be positively withdrawn thereby from the annular disc and into the bite between the rollers 248,290. From the rollers 248, 290, the flat will be directed into the bite between the roller pair 250, 292 from which the flat will be directed under a hood 302 provided by a cover plate 304, against a deflector 306, and downwardly through an opening 308 in the table 188. To aid in directing the lead edge of each flat into the bite between the rollers 248, 290, an arm 310 is provided that is carried in cantilever fashion by the pivot pin 298 about which the roller 288 pivots. A pair of idler rollers 312 carried by the arm 310 act as an anti-friction means for downwardly deflecting the leading edges of the flats as the latter approach the rollers 248, 290. A container (not shown) may be placed under the table 188 in position to receive the flats withdrawn from the annular disc.

As can best be seen in FIG. 2, the arcuate guide 218 diverges away from the periphery of the annular disc 182 from a point adjacent the flat-snatcher 244 to the discharge end of the arcuate guide. A horizontal, curved plate 314 is supported by the table 188 at a level just below the annular disc. The plate 314 extends radially outwardly from under the annular disc to the arcuate guide 218.

The successive pieces of letter mail slide off the annular disc 182 onto the plate 314 While remaining in edged condition against the arcuate guide 218. The cover member 230 terminates short of the discharge end of the plate 314 and supports adjacent its end a flexible finger 316 similar to the flap 240 in FIG. 3. The finger 316 urges each suc cessive piece of letter mail downwardly against the plate 314 as the successive pieces move oif the plate 314,

From the rotary edging and streaming unit 24, the pieces of letter mail can be directed to a horizontal stacker as disclosed in said US. patent application Ser. No. 15,336, now US. Patent No. 3,061,067, dated Oct. 30, 1962. Alternatively, the successive pieces can be directed through a letter turning unit 26 to a tandem facer canceller unit 28. Such a tandem facer canceller unit is disclosed, for example, in US. Patent No. 2,947,406 granted on August 2, 1960, to H, S. Hazelton, Jr. 7

The letter turning unit 26 is similar to the one depicted in said US. patent to H. S. Hazelton, Jr., in that the former turns each successive piece of letter mail about a horizontal axis whereas the latter turns the pieces The letter turning unit 26 includes two endless belts 318, 320. The belt 318 is entrained about two rollers 322 and 324, and the belt 320 is entrained about two rollers 326 and 328. The rollers 322, 324, 326 and 328 are positioned so that the two inner reaches of the belts are in face-to-face engagement with each other. As

can be seen in FIG. 2, the rollers 322, 326 are mounted for rotation about vertical axes and the rollers 324 and 328 are positioned so that the two inner reaches of the whereby the face-to-face engagement of said inner reaches of the belts 318, 320 gradually changes from horizontal at the input of the unit 26 to vertical at the output thereof. The belts 318 and 320 are driven in the respective directions to move the inner reaches thereof in the direction from the input to the output (right-to-left in FIG. 2) ofthe unit 26. As can be seen in FIG. 2 the roller '328 is mounted for rotation about a horizontal axis canted slightly from parallelism with the rotational axis of the roller 324. This provides a tendency [for the belt 320 to be urged in the direction of the deflector 238 but the effect is to balance and thereby overcome an inherent tendency for lateral shifting of the mutually engaging surfaces of the belts 318 and 320. The belts 318 and 320 aredriven by. a motor 330 which, through a pulley Wheel 332, drives a belt 334. The belt 334 drives a pulley wheel fixed to the shaft which mounts the roller 326 thereby to drive the belt 318. The belt 334 also drives a pulley wheel fixed on a shaft which also mounts a roller 336. A twist belt 338 is driven by the roller 336 and drives a roller 340. The roller 340, being mounted on the same shaft as the roller 324, drives the belt 320.

Each successive piece of letter mail moves off the discharge end of the edging and streaming unit 24 into the bite between the belts 318, 320 and is turned from a horizontal to a vertical attitude for discharge into the tandem facer-canceller 28 where the pieces are faced and the stamps thereon are cancelled.

The motor 214 for driving the rollers 94, the motor 272 for driving the annular disc 182 and the motor 330 for driving the letter turning belts 318, 320 are electrically connected as shown in FIG. 8. Ordinarily, the switch 140, 162 and 164 will be closed prior to closing of the main switch 138 to begin operation of the mail handling apparatus. A normally open, manually operable stop switch 342 is disposed in parallel relation with the switch 126 and operates, when momentarily closed, in the same manner as that when the switch 126 is closed. That is, the relay 152 is energized and the relay contactor 154 is closed to energize the solenoid 80 to stop the drive to the endless belt 50, the relay contactor 142 is opened to de-energize the motor 108 which drives the rollers 94, and the relay contactor 156 is closed to provide a hold-in circuit for maintaining the relay 152 in energized condition. In this manner the feeding of letter mail pieces to Since many changes can be made in the embodiment of the invention as particularly described and shown herein without departing from the scope of the invention, it is intended that this embodiment be considered as exemplary and that the invention not be limited except as warranted by the following claims.

'What is claimed is:

1. An apparatus for handling pieces of letter mail com prising:

(a) an annular disc having a circular periphery;

(b) the proper surface of said annular disc being formed of a material providing a coefiicient of friction between said surface and a piece of letter mail greater than the coefficient of friction between two piecesof letter mail;

(c) an arcuate guide extending about and adjacent to a substantial portion of the periphery of the annular disc;

(d) means operatively connected for rotatably driving said annular disc at :a sufiicient velocity that pieces of letter mail deposited on said disc are urged in the direction of rotation of the disc and into edged condition against said arcuate guide;

V (e) and means for withdrawing oversize pieces of let- 'ter mail from said disc; (f) said last-named means including a pair of opposed endless feed members providing a bite therebetween disposed radially inwardly of said annular disc; (g) and means operatively connected for rotatably driving said endless feed members in opposite directions for feeding radially inwardly of said annular disc any piecesof letter mail having a portion projecting radially inwardly of said annular disc into the bite between said endless feed members. 7 2. An apparatus for handling pieces of letter mail comprising:

(a) a disc having a circular periphery;

(b) the upper surface :of said disc being formed of a material providing a coefficient of friction between said surface and a piece of letter mail greater than the coefiicient of friction between two pieces of letter mail;

(c) an arcuate guide extending about and adjacent to a substantial portion of the periphery of the disc;

(d) means operatively connected for rotatably driving said disc at a sufiicient velocity that pieces of letter mail deposited on said disc are urged in the direction of rotation of the disc and into edged condition against said arcuate guide;

(e)v and a cover member extending from said guide radially inwardly of the latter and overlying a substantial portionof the radially outer margin of said disc thereby to confine a substantial amount of the 8 air between the cover member and the disc for movement in the direction of rotation of the disc as opposed to radially outward of the disc.

3. An apparatus for handling pieces of letter mailcomprising:

(a) a disc having a circular periphery;

(b) the upper surface of said disc being formed of-a material providing a coefficient of friction :between said surface and a piece of letter mail greater than the coeflicient of friction between two pieces of letter mail;

(c) an arcuate guide extending about and adjacent to asubstantial portion of the periphery of the disc;

(d) means operatively connected for rotatably driving said disc at a sufficient velocity that pieces of letter mail deposited on said disc are urged in the direction of rotation of the disc and into edged condition against said arcuate guide; 7

(e) and means for driving one of the longer edges, of each piece of letter mail into edged condition against said arcuate guide when the respective pieces of letter mail approaches said last-named means 'with one, of its shorter edges in edged condition against the arcuate guide;

(f) said last-named means comprising a presser member;

(g) means mounted said presser member for yieldable urging of the presser member against said disc at a location along the radially outer margin thereof;

(h) said location being spaced radially inwardly I of said arcuate guide a distance slightly greater than the maximum width of letter. mail pieces to be' handled whereby letter mailpieces having one of their shorter edges in edged condition against said arcuate guide are urged into increased driven engagement with said disc at said location to propel the leading longer edge thereof into edged condition against said arcuate guide.

4. An apparatus as set forth in claim 3 wherein said presser member comprises a roller whose outer periphery is defined by the radially outer ends of a plurality of, radially projecting flexible brush bristles.

References Cited by theExaminer 1 UNITED STATES PATENTS 2,982,407 5/1961 Craig et al. 209-91 3,061,067 10/1962 Liberty et al 198 30 FOREIGN PATENTS 631,881 6/1936 Germany.

M. HENSON WOOD, 111., Primary Examiner.

ROBERT B. REEVES, Examiner.

A. N. KNOWLES, Assistant Examiner. 

2. AN APPARATUS FOR HANDLING PIECES OF LETTER MAIL COMPRISING: (A) A DISC HAVING A CIRCULAR PERIPHERY; (B) THE UPPER SURFACE OF SAID DISC BEING FORMED OF A MATERIAL PROVIDING A COEFFICIENT OF FRICTION BETWEEN SAID SURFACE AND A PIECE OF LETTER MAIL GREATER THAN THE COEFFICIENT OF FRICTION BETWEEN TWO PIECES OF LETTER MAIL; (C) AN ARCUATE GUIDE EXTENDING ABOUT AND ADJACENT TO A SUBSTANTIALLY PORTION OF THE PERIPHERY OF THE DISC; (D) MEANS OPERATIVELY CONNECTED FOR ROTATABLY DRIVING SAID DISC AT A SUFFICIENT VELOCITY THAT PIECES OF LET- 